I don't think it's a problem or a feature. It's exactly what we saw on Reddit before it grew. It's not like Reddit had a limit on the number of subreddits a topic could have. As far as I'm concerned it'll eventually sort itself out just like it did on Reddit. It'll just take time to establish which communities are the largest. Eventually people will stop posting/subscribing to the communities that don't have as many people, and the largest one(s) will win out, just like they did on Reddit. This is an issue that requires patience. In the meantime, subscribe to them all and post to the one that has the most subscribers just like you would on Reddit if there wasn't a clear central community.

I think it's just a problem that will work itself out over time with more users. There are redundant subreddits as well, but as the overall userbase grew only one or two subs maintained the subscriber growth to continue showing up on r/all. And in cases where redundant subs both grew together, they evolved to be very different atmospheres. For example, r/games vs r/gaming; one is focused on news and discussion while the other is mostly memes. Both great subs, but started out nearly identical until they found their identity.

Why would I want 100 fragmented communities for the exact same thing?

I believe over time it'll sort out and one community will be dominant. But the reason you want this is so whoever got c/canada won't be dominant. If the mod of c/canada was a QAnon lizardpeople nut, you wouldn't need to make c/RealCanada because there's not a single real c/canada. You would make c/canada@lemmy.ml

But also, many communities were spread out even in reddit. Like r/traa and r/egg_irl.

The reason you want a 100 communities over one is what is happening over on Reddit. Make one big thing, and greed will take over. Make many smaller ones? Is significantly less likely to happen.

Tbh this isn't even unique to Lemmy. Even on reddit, creating a new subreddit is free. If you don't like the moderation or the general vibe of a subreddit, create a new one and build the community that you like. with the ethos that you see fit. That's how there's r/gaming, r/truegaming, r/games, r/pcgaming, r/gamernews, etc.

Reddit also only allowed comments in 2008, and Digg v4 was released in 2010. Therefore much of the reddit "canon" was developed after the Digg migration (e.g. today you tomorrow me, cumbox, forthewolfx, swamps of Dagobah, discoball, jolly ranchers, double dick dude, taco show, broken arms). Digg didn't have custom communities. Reddit did. And now Lemmy has custom communities in infinite instances. If there's going to be a Quit Reddit Day (maybe July 1st?) like Quit Digg Day, we're in the forefront of shaping Lemmy.

You might be completely incompatible with federation. I mean this with zero ill intention, it just might not be the alternative YOU are looking for. Reddit and lemmy are separate projects with separate goals and means. Centralization is what led to the issues leading to people exodusing from Reddit, but now everyone is upset that it's not centralized here. If you want one single set of users crammed into one single set of communities, this just isn't it by design.

As somebody who likes sharing my opinion and bickering about them, I've run afoul of power mods on Reddit in the past and been blanket banned from like 8 subs at once for liking firehouse subs over subway or some such nonsense. Here, if I'm banned from !AITA@lemmy.world I can still fiddle around on !AITA@lemmy.ml. I can spin up my own instance and start !AITA@lemmy.mything if I want.

It's important to remember that this is NOT REDDIT. This is a different project with different goals and different methods of achieving those goals. IIRC there are people trying to build a more 1 for 1 replacement for Reddit, and if that's what you want - great! Find one and enjoy it, but don't try to force lemmy to centralize and just become Reddit 2, because that's not the goal or intention of the project.